The proposed Cold Spring Harbor Laboratory Course on C. elegans is to be held July 27 - August 14, 2006, 2007, 2008, 2009, and 2010. This is an intensive three-week summer course aiming to introduce students to the practical aspects of using C. elegans as an experimental system. The program seeks to provide established researchers, postdoctoral fellows, and senior graduate students with limited or no previous C. elegans experience with enough theoretical and practical knowledge to allow them to productively introduce and use C. elegans as a tool in their home laboratories. Sessions are planned to cover the following topics: Worm Pushing;Anatomy and Development;Forward Genetics (mutagenesis, complementation, mapping);Generation of Transgenics;Analysis of Expression Patterns;Reverse Genetics (knockouts, RNA interference);and Worm Biochemistry. The course is taught by an energetic faculty team which is fully active in, and has made significant contributions to, the areas under study. This ensures that the newest techniques and ideas will be presented. The course's curriculum will continue to be reviewed and updated annually so that it reflects the recent advances in the fields under study. The faculty is supplemented by a series of seminar speakers who will present current research and application of advanced techniques in their fields of expertise.